1. Field of the Invention
Embodiments of the present invention generally relate to methods for forming a dielectric layer without containing hydrogen element. More particularly, this invention relates to methods for forming a hydrogen free silicon containing dielectric layer using a plasma enhanced chemical vapor deposition (PECVD) process.
2. Description of the Related Art
Display devices have been widely used for a wide range of electronic applications, such as TV, monitors, mobile phone, MP3 players, e-book readers, and personal digital assistants (PDAs) and the like. The display device is generally designed for producing desired image by applying an electric field to a liquid crystal that fills a gap between two substrates and has anisotropic dielectric constant that controls the intensity of the dielectric field. By adjusting the amount of light transmitted through the substrates, the light and image intensity, quality and power consumption may be efficiently controlled.
A variety of different display devices, such as active matrix liquid crystal display (AMLCD) or an active matrix organic light emitting diodes (AMOLED), may be employed as light sources for display devices which utilize touch screen panels. Transparent amorphous oxide semiconductor (TAOS) or metal oxide materials are widely used as semiconductor materials in display devices to improve device electrical performance. Examples of materials used for transparent amorphous oxide semiconductor (TAOS) or metal oxide materials include a-IGZO (amorphous gallium indium zinc oxide), zinc oxide, and the like. However, the transparent amorphous oxide semiconductor (TAOS) or metal oxide materials may be damaged by plasma during processing. Furthermore, hydrogen elements contained in the adjacent dielectric layers may detrimentally penetrate into the transparent amorphous oxide semiconductor (TAOS) or metal oxide materials, and may attack the transparent amorphous oxide semiconductor (TAOS) or metal oxide materials, thereby resulting in current leakage or other types of device failure. Furthermore, one of the damage may be found is the semiconductor properties may be lost and turn into a conductor due to the hydrogen donor effect.
Therefore, there is a need for a method for manufacturing the thin film transistor devices having improved electrical performance and stability.